[Haskell-cafe] an evil type hangs GHC

[Petr Pudlak]

Hi, I was playing with the following example I found in D.A.Turner's paper Total Functional Programming:

data Bad a = C (Bad a -> a)

bad1 :: Bad a -> a
bad1 b@(C f) = f b

bad2 :: a
bad2 = bad1 (C bad1)

    Thanks,
    Petr

To my surprise, instead of creating a bottom valued function (an infinite loop), I managed to send the GHC compiler (ver. 6.12.1) to an infinite loop. Could anybody suggest an explanation? Is this a GHC bug? Or is this "Bad" data type so evil that type checking fails?

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